Effects of extract, fractions and 2,3-dihydromyricetin-3-O-α-L-rhamnoside from Pradosia huberi (Ducke) Ducke on rat isolated mesenteric arteries

摘要: Pradosia huberi (Ducke) Ducke (Sapotaceae), an Amazonian species, is popularly known as "casca-doce" and used in the folk medicine for treatment of gastritis. The ethanol extract bark contains mainly polyphenolic compounds, which are to show a large number activities, including cardioprotective vasorelaxant effects. aim this study was evaluate pharmacological properties induced by P. (PHEE) fractions 2-3-dihydromyricetin-3-O-α-L-rhamnoside derived from extract, isolated rat mesenteric arteries. PHEE separated following were obtained: CHCl3, CHCl3:AcOEt (1:1), AcOEt, AcOEt:MeOH (1:1) MeOH. We MeOH fraction, identified 1H 13C NMR spectra compared with data literature. (1-100 µg/mL) concentration-dependent relaxations 10 µM phenylephrine-induced tone (EC50=17,1±2,9 µg/mL; Emax=87.4±2.9 %, n=8). fraction also relaxed rings (EC50=31±2.0 Emax=54±12.5%, n=6) but less effectively when PHEE. Both effects completely abolished after removal vascular endothelium. flavonoid ineffective eliciting vasorelaxation. demonstrates that possess effect, may be dependent upon not responsible effect.